Knee joint capsular disruption and repair

This application is a continuation of U.S. patent application Ser. No. 17/338,127, filed Jun. 3, 2021, which is a continuation of U.S. patent application Ser. No. 16/116,503, filed Aug. 29, 2018, which is a continuation of U.S. patent application Ser. No. 15/662,631, filed Jul. 18, 2017, which is a continuation of U.S. patent application Ser. No. 15/596,015, filed May 16, 2017, which claims the benefit under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 62/337,059, filed on May 16, 2016, and entitled “Meniscal Capsular Disruption and repair”, and to U.S. Provisional Patent Application Ser. No. 62/470,473, filed Mar. 13, 2017, and entitled “Knee Joint Capsular Disruption And Repair, all of which are incorporated herein by reference in their entireties.

The disclosure herein describes methods of treating extrusion of the meniscus, which can possibly delay the early onset of osteoarthritis, further meniscal damage, and meniscal root pathology.

The meniscus is a crescent-shaped cartilage pad that functions to cushion and stabilize the knee joint. In particular, the meniscus acts as a shock absorber between the femur and the tibia. A common knee injury is meniscal extrusion, which occurs when the meniscus drifts from its anatomical position in the knee. When the meniscus is in an extruded position, there is reduced function of the meniscus in cushioning and stabilizing the knee joint. Meniscal extrusion is often associated with meniscal degeneration, a meniscal tear (e.g., a radial tear, a longitudinal tear, or an oblique tear), a torn meniscal root, and/or osteophyte formation.

Current methods of treating a meniscal extrusion include both non-surgical treatment and surgical repair. Non-surgical treatment is often attempted prior to surgical repair, and example non-surgical treatment includes physical therapy and/or insertion of biologics to facilitate the healing of the meniscus. However, in the event that non-surgical treatment is not successful in treating the meniscal extrusion, surgical repair can be performed to treat the meniscal extrusion. Surgical repair is usually performed arthroscopically, and a knee arthroscopy to treat the meniscus typically includes repairing any meniscal tear(s) and/or repairing a torn meniscal root. Knee arthroscopy can also include removal of osteophytes that have formed.

Current surgical repair methods for treating a meniscal extrusion have various drawbacks. For example, current methods do not treat the underlying injury that results in a meniscal extrusion. The meniscus drifts due to a disruption in the capsule of the knee, whereby the capsule becomes detached from at least one structure of the knee joint (e.g., the meniscus, tibial periosteum, femoral periosteum, etc.) and/or the meniscotibial ligament (MCL) detaches from its insertion point. Capsular disruption can occur concomitantly with a meniscal root tear. Alternatively, capsular disruption can occur, followed by meniscal extrusion, which then leads to a meniscal root tear. Current methods for treating a meniscal extrusion do not adequately address or treat the capsular disruption. Since current surgical repair methods do not treat this capsular disruption, the underlying injury that results in the meniscal extrusion remains after current surgical repair methods. Thus, surgical repair methods, and symptom relief, may only be temporary since the underlying injury remains. After time, the surgically repaired meniscus can begin to extrude again.

Improved systems and methods for repairing a meniscal extrusion are needed. In particular, systems and methods that treat the underlying injury that results in a meniscal extrusion are needed. Systems and methods for teaching improved systems and methods for repairing a meniscal extrusion are also needed.

A capsular disruption can result in meniscal extrusion, which occurs when the meniscus drifts from its anatomical position in the knee. The meniscus drifts medially or laterally (“extruding” from the knee joint). The meniscus drifts due to a disruption in the capsule of the knee, whereby the capsule becomes detached from at least one structure of the knee joint (e.g., the meniscus, tibial periosteum, femoral periosteum, etc.) and/or the meniscotibial ligament detaches from its insertion point. The capsule can develop laxity and/or tears through degeneration or trauma to the three layer structure of the medial and/or lateral capsule. Additionally or alternatively, the capsule can develop laxity and/or tears through degeneration or trauma to the meniscotibial fibers of the meniscotibial ligament. Capsular disruption can occur concomitantly with a meniscal root tear. Alternatively, capsular disruption can occur, followed by meniscal extrusion, which then leads to a meniscal root tear. A meniscal root tear is often associated with the subsequent short or long term development of osteoarthritis.

As a particular example of capsular disruption resulting in meniscal extrusion, the medial inferior knee capsule can begin peeling away from the tibia, and this peeling away can lead to meniscal extrusion. The medial inferior knee capsule can peel away from the tibia for various reasons, such as trauma and/or degeneration. In an example, the trauma and/or degeneration causes coronary fibers of the meniscotibial ligament to detach from the tibia. When the medial inferior knee capsule peels away from the tibia, the meniscus loses a portion of support, and the anterior horn of the medial meniscus can incur further trauma. This further trauma leads to a disruption of this attachment point of the meniscus, allowing the meniscus to extrude to a greater distance. When the meniscus is in the extruded position, there is reduced function of the meniscus in cushioning and stabilizing the knee joint. Continued micro-motion of meniscus extrusion can further progress the disruption of the capsule from the tibia. As the meniscus further extrudes, the posterior horn of the meniscus can become avulsed.

Although the above example describes a progressive extrusion from the anterior to the posterior aspect of the knee, other example progressions are possible as well. For instance, it is also possible that a traumatic event or degeneration can cause a disruption to the posterior horn of the medial meniscus, thereby leading to the progressive extrusion of the meniscus from the posterior to anterior aspect of the knee. Additionally, although the above example describes a capsular disruption of the medial inferior knee capsule, in other examples the lateral knee capsule peels away from the tibia. Furthermore, although the above examples describe the knee capsule peeling away from the tibia, the knee capsule can peel away from other structures of the knee joint. For instance, in other examples, the knee capsule peels away from the femur.

Disclosed herein are methods of repairing a capsular disruption to re-attach the capsule to a knee structure. A repair of capsular disruption can be performed concomitantly with a meniscal root repair. If the meniscal root is not torn, the capsular disruption can be repaired so the meniscus does not extrude further, and the condition does not progress to a torn meniscal root. An embodiment includes inserting one or more anchors through the capsule. The anchor can be inserted into a knee joint structure to re-attach the capsule to that structure.

The methods and systems in accordance with the present disclosure beneficially provide improved methods and systems for repairing a meniscal extrusion. In particular, the disclosed methods and systems treat the underlying injury of capsular disruption that leads to a meniscal extrusion. By treating this underlying injury, the disclosed methods and systems of repairing a meniscal extrusion result in a more effective repair of the meniscal extrusion compared to existing repairs of meniscal extrusions. Furthermore, in accordance with example embodiments, the disclosed methods and systems also provide improved methods and systems for teaching and/or practicing repair of a meniscal extrusion.

In an example in accordance with the present disclosure, methods of repairing capsular disruption are described. The methods include inserting one or more anchors through a knee joint capsule of a knee. The method further includes inserting the one or more anchors into a knee joint structure to secure the knee joint capsule to the knee joint structure.

In another example in accordance with the present disclosure, methods of creating a capsular disruption are described. A method includes placing an instrument between a knee joint capsule of a knee and a knee joint structure of the knee. A method then includes disrupting the attachment of the knee joint capsule from the knee joint structure by physically elevating the instrument to force a capsular disruption. In an embodiment, the instrument has a flat surface (e.g., a banana blade) so soft tissue is not cut when the instrument is elevated.

In another example in accordance with the present disclosure, methods to teach or practice repairing meniscal extrusion are described. A method includes using a cadaveric knee to teach or practice a method of repairing a capsular disruption, wherein said method comprises (i) inserting one or more anchors through the knee joint capsule and (ii) inserting the one or more anchors into the knee joint structure to secure the knee joint capsule to the knee joint structure. In another embodiment, a cadaveric knee is used to teach repairing a meniscal tear in combination with repairing a capsular disruption.

In another example in accordance with the present disclosure, a method to teach or practice repairing a meniscal extrusion is described. The method includes using a synthetic knee to teach or practice repairing the meniscal extrusion, wherein the synthetic knee comprises a synthetic knee joint capsule and a synthetic knee joint structure. Using a synthetic knee to teach or practice repairing the meniscal extrusion includes (i) inserting one or more anchors through a synthetic knee joint capsule of a synthetic knee and (ii) inserting the one or more anchors into a synthetic knee joint structure to repair a capsular disruption by securing the synthetic knee joint capsule to the synthetic knee joint structure.

In another example in accordance with the present disclosure, a knee model is described. The knee model includes at least part of a tibia, at least part of a femur, a detachable meniscus, a detachable knee capsule, and a detachable meniscotibial ligament, wherein all of the components are synthetic.

The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or can be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings.

Disclosed embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all of the disclosed embodiments are shown. Indeed, several different embodiments may be described and should not be construed as limited to the embodiments set forth herein.

A method of repairing a capsular disruption to re-attach the capsule to a structure is disclosed herein. Meniscal extrusion can occur when there is capsular disruption, i.e., detachment or tearing of the knee capsule from at least one structure of the knee joint. In an embodiment, a capsular disruption tear can be less than 0.5 mm, about 0.5 mm, about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, or about more than 10 mm. Medial or lateral drift of the meniscus (i.e., meniscal extrusion) can be about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about more than 75%. In an embodiment, injuries can be graded according to the length of the tear in combination with the percent extrusion. For example, a Grade 1 injury occurs when there is minimal capsular disruption with a 10% or less meniscal extrusion. A Grade 2 injury occurs when there is a 3 mm or less tear with a 25% or less meniscal extrusion. A Grade 3 injury occurs when there is an 8 mm or less tear with a 50% or less meniscal extrusion. A Grade 4 injury occurs when there is an 8 mm or more tear with a 50% or more meniscal extrusion. Other meniscal-injury grading scales can be used as well and may change over time with greater research after recognition of the underlying injury.

illustrate various example meniscal extrusions. In particular,illustrates a kneehaving an example Grade I injury. In this example, there is a 10% or less meniscal extrusion. In this example injury, there is also a sprain with edema in the tissue or associated marrow attachment of the meniscotibial ligament. Furthermore, in this example injury, there is no medial collateral ligament (MCL) sprain or involvement other than edema, and there are no or minimal osteophytes present.

illustrates a kneehaving an example Grade II injury. In this example, there is a 25% or less meniscal extrusion. There is also a 3 mm or less capsule disruption tearin which the capsuleis separated from the tibia. Furthermore, in this example, there can be mild degeneration, such a minimal meniscal degeneration or cleavage tear. For instance,shows mild degeneration. In this example injury, there is also a mild sprain of the MCL, and there are no or minimal osteophytes present. The meniscal extrusionis reducible with compartment dynamic off-loading.

illustrates a kneehaving an example Grade III injury. In this example, there is a meniscal extrusionof approximately 25-50%. There is also a 8 mm or less capsule disruption tearin which the capsuleis separated from the tibia. Furthermore, in this example there can be moderate meniscal degeneration and/or osteophyte formation. For instance,shows moderate degenerationand osteophyte. In this example, the meniscal extrusionis reducible with compartment dynamic off-loading. However, due the osteophyte formation, the meniscusmay or may not be fully reducible.

illustrates a kneehaving an example Grade IV injury. In this example, there is a meniscal extrusionof approximately 50% or more. There is also a 8 mm or less capsule disruption tearin which the capsuleis separated from the tibia. Furthermore, in this example there can be severe meniscal degeneration or tearing with osteophytes present. For instance,shows severe degenerationand osteophytes-. In this example, the meniscal extrusionis not substantially reducible with compartment dynamic off-loading.

Disclosed herein are methods of repairing a capsular disruption that produce meniscal extrusions as shown in. An example method of repair includes inserting one or more anchors through the capsule. The anchor can be inserted into a knee joint structure to re-attach the capsule to that structure. Any suitable anchors are possible. For instance, in an example embodiment, the anchor is a suture anchor (knotless or knotted; e.g., a SutureTak® anchor, Quattro® Link knotless anchors, Twinfix® anchors, Bioraptor® anchors, Spyromite® anchors, Dynomite® anchors, Osteoraptor® anchors, Raptomite® anchors, JuggerKnot® anchors, JuggerKnotless® anchors, etc.), a soft tissue anchor (e.g., Eclipse™ soft tissue anchor, Piton™ soft tissue fixation implant, etc.), or the like. In another example, the anchor is a staple. Other anchors are possible as well.

In an example embodiment, a method for repairing a capsular disruption is performed to repair a capsular disruption before a meniscal extrusion has occurred. In another example, the method for repairing a capsular disruption is performed to repair a capsular disruption that resulted in an associated meniscal extrusion. For instance, the method for repairing a capsular disruption could be used to repair the capsular disruptions resulting in meniscal extrusions shown in.

An example method can involve positioning an arthroscope in a position to allow visualization of the knee joint capsule and the knee joint structure. The example method can involve placing a spinal needle through the skin into the knee joint space to mark an area above the meniscus. The example method can involve visualizing the spinal needle with the arthroscope to identify a location for inserting one or more anchors through the knee joint capsule. The example method can involve, for each anchor of the one or more anchors, drilling a socket in the bone for inserting the anchor into the bone. The method can involve inserting the one or more anchors through the knee joint capsule of a knee. The example method can involve inserting the one or more anchors into the drilled socket to secure the knee joint capsule to the knee joint structure. The example method can involve securing flexible strands (e.g., suture, suture tape, etc.) from one anchor to another anchor.

This example method is described in further detail with reference to.illustrates a kneeupon which the example method is performed. In this example, kneeis illustrated as a synthetic knee model. However, in other examples, the kneeis a knee of a patient. In yet other examples, the kneeis a cadaveric knee.

The kneeincludes a knee joint capsuleand a knee joint structure. As seen in, the example method involves positioning an arthroscopein a position to allow visualization of the knee joint capsuleand the knee joint structure. The example method also involves placing a spinal needlethrough the skin (not shown) into the knee joint space. Furthermore, the example method involves visualizing the spinal needlewith the arthroscopeto identify a location for inserting one or more anchors through the knee joint capsule.

In the example of, the area of the knee joint capsulethrough which the one or more anchors are inserted is the medial capsule. However, in other example embodiments, an area of the knee joint capsulethrough which the one or more anchors are inserted is the lateral capsule. Furthermore, in the example embodiment of, the knee joint structureinto which the one or more anchors are inserted is the tibia. However, in other example embodiments, the knee joint structureis the femur.

In the illustrated example, the one or more anchors include a first anchor and a second anchor.illustrate identification of the location for inserting the first anchor and the insertion of the first anchor. As seen in, the spinal needleis placed in the knee joint capsuleand is viewed with the arthroscopeto identify a location for inserting the first anchor. The spinal needlecan enter through the knee joint capsuleabove the meniscus and into the joint space. The anchor placement can then be determined a certain distance distal to this spinal needlefor capsular repair on the tibia. The method then involves making an incision in the knee joint structurefor inserting the first anchor into the knee joint structure. In particular, drill pin(see) can be used to drill a hole for inserting the first anchor into the knee joint structure. A drill guide(see) can be used to guide the drill pin. The drill guidewith an anchor inserted through the cannulation of the drill guideis used to place the anchor into the knee joint structure(see). The first anchor(see) is placed in the drilled hole. The first anchoris placed below the joint line(see) and through the capsuleat the anterior distal portion of the capsule. In an example embodiment, the insertion of the first anchor is percutaneously inserting the anchor.

illustrate identification of the location for inserting the second anchor and insertion of the second anchor. The spinal needleis placed in the knee jointand is viewed with the arthroscopeto identify a location for inserting the second anchor. The method then involves drilling a socket in the knee joint structurefor inserting the second anchor. In particular, as seen in, drill guideis used to drill a hole through the capsuleand into the knee joint structure. The second anchor(see) is then placed in the drilled hole. In this example embodiment, the second anchoris placed posterior to the first anchor.

In an example embodiment, the second anchoris placed within about 2 cm of the first anchor. In a more particular example, the second anchoris about 1 to about 2 or about 1 to about 1.5 cm from the first anchor. However, other distances between the anchors are possible as well (e.g., about 0.3, 0.4, 0.5, 0.6., 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0 cm, or more (or any range between about 0.3 and 3.0 cm)).

Although in this example the spinal needleis inserted multiple times and/or into multiple locations so as to determine the locations for inserting the two anchors, in other examples the spinal needlecould be inserted a single time and/or at a single location. The locations for inserting the one or more anchors could then be identified relative to position of the spinal needle. For instance, in an example embodiment, the spinal needleis placed between the femur and tibia at knee joint line, and the arthroscopeis used to confirm that the spinal needleis positioned at the joint line. The medical provider could select a distance from the knee joint lineat which to insert the one or more anchors through the knee joint capsule. The anchor is typically placed about 3 mm to about 5 mm below the knee joint line. The medical provider could then identify the location(s) for inserting the one or more anchors through the knee joint capsule based on the position of the spinal needle at the joint line. In particular, the spinal needleat the joint linecan act as a guide for the medical provider so the medical provider is able to easily visualize precisely where the joint line is located. This will help to ensure that the medical provider places the anchors,a desired distance below the joint line.

Embodiments of the method of repair include bridging of the anchors by any type of flexible strand (e.g., suture, suture tape, etc.) With reference to, the method involves securing sutures from one anchor to another anchor. First anchoris a suture anchor that includes sutures, and second anchoris a suture anchor that includes sutures(see). A suture leadfrom first anchoris fed into second anchor(see). The suture leadis then tightened between the first anchorand the second anchor(see). Suture leadfrom the second anchoris then threaded through to first anchorand tightened (see). Securing the sutures from one anchor to another creates a bridge(see) between the first anchorand the second anchor. This bridgefunctions as a band that spans capsular tissueand helps to secure the capsuleto the knee joint structure. This bridgealso helps to prevent further meniscal extrusion.

Although the example embodiment illustrated inincludes inserting two anchors,to secure the knee joint capsuleto the knee joint structure, more or fewer anchors are possible. For instance, in an example embodiment, three anchors are used to secure the knee joint capsuleto the knee joint structure. In an example, the first and second suture anchors about 1 cm to about 2 cm apart, and the second and the third anchors are about 1 cm to about 2 cm apart. A suture lead from a first anchor is fed into a second anchor; suture lead from the second anchor is fed into a third anchor; and a suture lead from the third anchor is fed into the first anchor. In another example, one anchor is used to secure the knee joint capsuleto the knee joint structure. In yet another example, four or more anchors are used to secure the knee joint capsuleto the knee joint structure.

In general, the number of anchors inserted to secure the knee joint capsuleto the knee joint structurecan depend on the size of the capsular disruption. For instance, a suitable number of anchors is selected so as to cover the expanse of the tear and so that the anchors are within about 2 cm or less of one another. Typically, more anchors are selected for a larger tear than for a smaller tear. As a particular example, a common capsular disruption tear is approximately 2.5 cm. In an example, three anchors can be used for such a tear to secure the knee joint capsuleto the knee joint structure. For instance, a first anchor could be placed at or near the beginning of the tear (e.g., at the 0 cm mark), a second anchor could be placed at or near the middle of the tear (e.g., 1.25 cm mark), and a third anchor could be placed at or near the end of the tear (e.g., at the 2.5 cm mark). On the other hand, for a smaller tear, such as a 1-1.5 cm tear, one or two anchors can be inserted to secure the knee joint capsuleto the knee joint structure. Other examples are possible as well.

Furthermore, although the illustrated example involved inserting suture anchors and bridging those suture anchors together, other example anchors are possible as well. In general, any suitable tissue anchors could be used. Other example methods include other knotless anchors bridged with FiberTape® or SutureTape™, or a combination of knotted and knotless anchors and sutures. Furthermore, in some example embodiments, the tissue anchors are independent and are not bridged together.

In addition to inserting one or more anchors to secure the knee joint capsuleto the knee joint structure, additional steps can be taken to further treat the meniscal injury. For instance, in an example embodiment, the repair of capsular disruption can be performed concomitantly with a meniscal root repair. If the meniscal root is not torn, the capsular disruption can be repaired so the meniscus does not extrude further, and the condition does not progress to a torn meniscal root and/or the development of osteophytes. Additionally or alternatively, the repair of capsular disruption can be performed concomitantly with repair of other meniscal tears, such as a radial tear, a longitudinal tear, or an oblique tear. Furthermore, the repair of capsular disruption can be performed concomitantly with removal of osteophytes formed in the knee joint.

Additional steps can also be taken to enhance the healing environment for a meniscal injury. In an example embodiment, the method includes roughening a knee joint structureto induce bleeding, so as to provide an enhanced healing environment. In an embodiment, the method includes using a rasp or like instrument to roughen medial tibial metaphysis at the level of the lesion.

In an example embodiment, the method includes augmenting the repair of the at least one of the capsular disruption or the meniscal extrusion by inserting a biological product into the knee, so as to stimulate healing of the capsular disruption and the meniscal extrusion. Any suitable biological product can be inserted to stimulate healing. For instance, in an example embodiment, the biological product is stem cells (e.g., stromal stem cells), platelet-rich plasma (PRP), a tissue graft (e.g., adipose, amnion, chorion, etc.), or combinations thereof. Other example biological products include bone marrow concentrate (BMC), bone marrow aspirate (BMA), growth factors, angiogenin, transforming growth factor-02 (TGF-(32), tissue inhibitors of metalloproteinases (e.g., TIMP-1 and TIMP-2)), and growth factors, such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), TGF-0 (transforming growth factor-(3), and combinations thereof. The biological product can be obtained from the patient to be treated or from another source. In an example, inserting the biological product into the knee takes place prior to (i) inserting the one or more anchors through the knee joint capsule of a knee and (ii) inserting the one or more anchors into a knee joint structure to secure the knee joint capsule to the knee joint structure. In another example, inserting the biological product into the knee takes place after (i) inserting the one or more anchors through the knee joint capsule of a knee and (ii) inserting the one or more anchors into a knee joint structure to secure the knee joint capsule to the knee joint structure.

In an embodiment, the meniscus and/or the methods described herein can be visualized using an arthroscope. The arthroscope is a diagnostic and therapeutic device utilized with minimally invasive orthopedic surgical procedures. The arthroscope provides direct visualization within the orthopedic articulating joint to assess or diagnose such anatomical structures as the meniscus, ligaments, tendons and articular surfaces.

The arthroscopist can follow a standardized approach for a complete diagnostic knee arthroscopy. In an example embodiment, a diagnostic arthroscope includes visualization of areas around the patella including the suprapatellar pouch, medial and lateral gutter, intracondylar notch, posterior medial and lateral compartments as well as the medial and lateral compartment. Each compartment has specific anatomy to investigate. This investigation can utilize an arthroscopic probe from the opposite anterior portal. The probe allows the arthroscopist to manipulate various anatomical structures to determine abnormalities to these structures.

An anterolateral portal can initially be established prior to establishing an anteromedial portal. The arthroscope and arthroscopic probe can be interchanged between either portal for maximum efficiency of the arthroscope or arthroscopic probe. Posteromedial and posterolateral portals can be established to fully appreciate the structures in the posterior aspect of the knee joint.

The meniscus can be viewed intra-articular with the arthroscope. Meniscus hyper-mobility can be assessed with the aid of an arthroscopic probe. The location of capsular disruption leading to meniscal extrusion can be appreciated through the arthroscope as well as other diagnostic tools. Utilizing the arthroscope for an intra-articular perspective of the meniscus, the medical provider can locate the beginning and ending point of extrusion that would correlate with capsular defect. In an example embodiment, the medical provider inserts a needle from the outside of the knee into the joint, verifying arthroscopically that the needle is at the starting point of meniscal extrusion/capsular disruption. The needle is used to mark the beginning and end points of the extrusion in the coronal plane (anterior to posterior aspect), and also to assess anchor placement in the transverse plane (superior and inferior aspect).

The arthroscope can also be used to verify the presence of a meniscal and/or capsular lesion. With direct arthroscopic visualization, a capsular lesion can be produced and assessed and/or evaluated for research purposes.

In addition to or alternative to visualizing the meniscus and/or methods described herein with an arthroscope, the meniscus and/or the methods described herein can be visualized using other means. For instance, in other examples, the meniscus and/or the methods described herein can be visualized using ultrasound, magnetic resonance imaging (MRI), and/or open dissection with visual inspection of the medial or lateral capsule structure with its associated bony attachment. Meniscal extrusion can be identified by palpation, visualization (e.g., ultrasound), etc. In an example, a capsular disruption and meniscal extrusion can be identified via ultrasound, Mill, etc. prior to any procedure or teaching procedure (e.g., on a cadaveric knee).

illustrate example ultrasounds.illustrates an ultrasoundshowing an intact capsuleand an intact meniscuson a cadaveric knee.illustrates an ultrasoundshowing meniscal extrusion of the meniscusmedially. The capsule is detached from the meniscus and/or tibial periosteum.illustrates another example ultrasoundshowing further extrusion of the meniscusmedially. A detailed diagnosis of the meniscal extrusion can be performed using ultrasound in both a static and dynamic manner. In an example, the diagnosis involves applying a valgus moment and/or a varus moment to the knee and determining whether the meniscal extrusion is reducible based on the movement of the meniscus during the valgus and/or varus movement. Additionally or alternatively, a detailed diagnosis can be performed using ultrasound elastography (see, e.g., Drakonaki et al.,2012, 85: 1435-1445).

Also disclosed herein are methods of producing a meniscal extrusion injury in a cadaveric knee. A meniscal extrusion injury in a cadaveric knee provides a model to teach diagnosis and/or repair of meniscal extrusion. An example method for disrupting a knee joint capsule of a knee (e.g., a cadaveric knee) from a knee joint structure includes placing an instrument (e.g., a single sided banana blade scalpel) between a knee joint capsule of a knee and a knee joint structure of the knee. The example method then involves disrupting the knee joint capsule from the knee joint structure by physically elevating the instrument to force a capsular disruption.

This example method is described in further detail with respect to.illustrates an example kneewhere the knee joint capsuleis substantially intact with the tibia. In an example, kneeis a cadaveric knee. An instrument such as a probe or a scalpel (e.g., a banana blade scalpel) is placed between the knee joint capsuleand tibia. For instance, the instrument can be placed at pointbetween the knee joint capsuleand tibia. After being placed between the knee joint capsuleand tibia, the instrument is physically elevated to force a capsular disruption. For instance, the instrument can be physically elevated along the y-axis. Although in this example the instrument is physically elevated along the y-axis, the instrument can be physically elevated in other directions as well. In general, the instrument can be elevated in any direction suitable to disrupt the capsule from the knee joint structure (e.g., the tibia or the femur). The extent of the forced capsular disruption can be controlled based on the force applied to physically elevate the instrument. Further, the extent of the capsular disruption can be measured by visualizing the knee with ultrasound, MM, or other visualization mechanisms.

In an embodiment, disrupting the knee joint capsulefrom the tibiaby physically elevating the instrument to force a capsular disruption comprises tearing coronary fibers of a meniscotibial ligament.illustrates example coronary figures of a meniscotibial ligament. This close-up view of the medial capsuleillustrates the three layer structure of the medial capsule, including (i) crural fascia, (ii) superficial portionof the MCL, and (iii) the deep portionof the MCLincluding meniscofemoral and meniscotibial extensions of the deep MCL. In particular,illustrates coronary fibers of the meniscotibial ligamentand coronary fibers of the meniscofemoral ligament. Disrupting the knee joint capsulefrom the tibiacan include tearing the coronary fibers of the meniscotibial ligamentfrom the tibia.